The development of personal cleansers (including, without limitation, liquid hand soaps, body washes, shampoos, bath washes, and the like) has long been driven by the challenge of providing a combination of performance properties such as good foaming, good cleansing, enhanced mildness, improved skin feel, and attractive product appearance. Specifically, while a certain component within a personal cleanser may enhance one property, it will often do so at the detriment of another important property of the cleansing product. For example, a composition may enhance skin conditioning by incorporating emollients at the expense of foaming. Therefore, those in the relevant art have been seeking new formulations to help achieve the balance of desirable performance properties.
It is well known that a personal cleanser is typically aqueous and comprises one or more mild detersive surfactants and/or soaps. For example, conventional hand cleansers, body washes, shampoos, or liquid soap typically comprise a synthetic detersive and/or fatty acid soap and one or more foam stabilizing, wetting, or emulsifying surfactants.
Similarly, personal cleansers based on synthetic detergents often impart poor skin feel during and after use, and require additives to improve such tactile aspects of performance. Further, synthetic detergents often degrease the skin to an excessive degree thereby resulting in dry skin.
Therefore, researchers have strived to develop a personal cleansing formulation with low irritation, good tactile characteristics, good foaming, and good cleansing properties. Examples of developments in synthetic personal cleansing formulations include U.S. Pat. No. 4,664,835, which describes a washing and cleansing formulation containing a synthetic surfactant and an anionic polymer; U.S. Pat. No. 5,646,100, which describes a liquid personal cleansing formulation containing an anionic surfactant, a betaine, and an alkyl polyglycoside; and U.S. Pat. No. 5,310,508, which describes a personal cleansing composition containing a salt of alcohol ethoxy glyceryl sulfonate (“AGS”) and a second synthetic surfactant.
Examples of liquid cleansers which provide both cleansing and moisturizing functions include U.S. Pat. No. 5,650,384, which describes cleansing and moisturizing emulsions containing two phases. One of the phases is a moisturizing phase comprising 0.5% to about 33.5% of a skin conditioning ingredient, which may be a vegetable oil, petrolatum or silicone oil, among others. Another patent, U.S. Pat. No. 5,965,500, describes liquid cleansing compositions containing levels of oil/emollient equal to or greater than the level of surfactant. The surfactant system contains at least one anionic surfactant, which may be an aliphatic or aromatic sulfonate. U.S. Pat. No. 5,661,189 describes liquid cleansing compositions which contain from 0.1 to 15% of a “benefit agent” which may be, for example, vegetable, mineral or silicone oils.
These developments, and other conventional personal cleansers, however, fail to provide the desired balance of skin feel (i.e., skin softness, smoothness, moisturization, no greasy and low skin irritation), foaming, lather, and cleansing. Accordingly, there remains a need for a personal cleansing formulation that provides enhanced skin feel, low skin irritation, low skin drying, good cleansing ability, good foaming, and good rinsability characteristics/properties.